This invention pertains to a device providing a sterile conduit for non-invasive entry into the uterine cavity.
A number of conditions require non-invasive entry into the uterine cavity, for both therapeutic and diagnostic purposes. Such access is provided through the canal of the uteral cervix, transvaginally. For diagnostic purposes, contrast media may be injected into the cervical canal and radiography carried out, both to establish the outline of the uterine cavity and/or patency of the Fallopian tubes. Alternatively, ultrasonography can be used following gas insufflation, or a fiberoptic device can be introduced into the uterine cavity for direct inspection. Yet another means of providing access is to introduce catheters into the cervical canal, and input contrast media into the uterine cavity directly.
Recently described in an article entitled "Fallopian Tubes Obstruction: Selective Salpingography and Recanalization," Radiology, May 1987, number 167, pp. 511-514, is the use of a coaxial catheter system with a wire guide for transvaginal recanalization of stenosed Fallopian tubes, also carried out through the cervical canal. This procedure usually is performed in conjunction with diagnostic radiography prior to and following recanalization. Inasmuch as the stenosis usually is a result of inflammatory changes and is one major cause of female infertility, and since surgical transabdominal recanalization of the Fallopian tubes has been shown to meet with only limited success, development of new instrumentation enabling use of non-invasive procedures, such as the radiological approach, is of major importance.
Non-invasive access to the Fallopian tubes is also utilized for the purpose of artificial insemination. Typically, this procedure, which has been shown to be at least twice as effective as in vitro fertilization, involves harvesting the egg and injecting a mixture of sperm and egg into the Fallopian tubes. While this procedure can be carried out under hysteroscopic, radiographic, or ultrasonographic control, the common denominator of all these procedures is access through the cervical canal and insertion of catheters into the tubes. Another possible use of selective tubal catheterization is to inject compositions for the purpose of reversible sterilization.
The internal genital organs must be protected from infectious agents normally or pathologically present in the vaginal environment. A reliably attachable conduit system for safe introduction and manipulation of catheters and other devices, and for the introduction of radiographic contrast media into the uterine cavity and the tubes for the purpose of radiography, does not yet exist. Devices for the introduction of radiographic contrast media for the purpose of uterine/tubal radiography have been described previously, but they have a number of drawbacks, and they do not allow introduction of catheters.
One prior art approach involves grasping the cervix with a tennacula and inserting a rubber cannula into the cervix under tension, with the distinct disadvantages of discomfort to the patient and bleeding from the cervix, as well as incomplete sealing of the cervical canal.
Another prior art device is a large diameter catheter ("Foley catheter") equipped with an occluding balloon into the cervical canal. While sealing with the balloon's inflation is adequate, the Foley catheter does not permit rectification of the uterus by traction, which is often necessary for radiodiagnostic presentation.
Another prior art device, "Malmstrom's cannula", employs a cup appositioned to the cervix and held in position by vacuum, forcing a conical rubber cannula into the canal. The seal is accomplished by pressure against the cervical mucosa, but this is not always successful, especially when the entrance to the cervix has been lacerated by previous births. Also, the device is complicated, consisting of a large number of parts and requiring considerable manipulation for each resterilization which can be carried out only after thorough dismantling and cleaning. The device does not allow insertion of a catheter.
Another prior art device is the Kidde cannula, devised to seal the canal's orifice with a rubber cone, and to enter the uterine canal with steel tubing. This poses a risk of injury to the uterine cavity, as described, for example, by Winfield, A. C. and Wenz, A. C., "Techniques and Complications of Hysterosalpingography," in Williams and Wilkins (eds.), Diagnostic Imaging of Infertility, 1987, pp. 9-26. This device does not permit introduction of a coaxial or single catheter for selective tubal catheterization or fiberscope introduction.